st: Re: random sample

["Michael Blasnik" <michael.blasnik@verizon.net>]

...
If you can read in the dataset, then I'd recommend using the -sample- 
command.  But if you can't, then you can :

use myfile if uniform()<.1

which will select about 10% of the observations.  If you want exactly 10%, 
then use something bigger than 0.10 and then use -sample- :

use myfile if uniform()<.15
sample 100000

You probably want to set the random number seed before any of these 
approaches if you want replicable results.

Michael Blasnik


----- Original Message ----- 
From: "Marcella Sapun" <msapun@jhu.edu>
To: <statalist@hsphsun2.harvard.edu>
Sent: Thursday, October 26, 2006 10:57 AM
Subject: st: random sample



> Dear statalisters:
>
> I want to read randomly 10% of a data set that contains about 1 million
> records and 100 variables. How do I do that in stata?
>
> Thanks,
>
> Marcella
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